Second law analysis of an integrated parabolic trough photovoltaic thermal system

Abstract

The present work discusses the second law of thermodynamics analysis based on experimental investigation of newly designed integrated parabolic trough photovoltaic thermal system. The hybrid system consists of integration of PV module within the receiver tube of parabolic trough having semi circular absorber tube. To cool down the PV module, owing to high concentration, a provision was made to flow water through front surface and rear side of the PV module. The experimentation was carried out and based on the data generated on field, the second law analysis was carried out and its various parameters were evaluated. Besides irreversibility and exergy losses, the exergetic efficiency was estimated using the following cases (a) efficiency calculation without accounting exergy losses (b) by taking exergy destruction and losses occurring in the setup and; (c) by considering only exergy destruction. On comparison of efficiency obtained from Case III with other two cases, it was found out that second law efficiency of third case was higher than first and second. The efficiency obtained in Case III varied from 38.3 - 44.8%, 31.5 - 38.0% and 26.2 -31.7%, when inner tube mass flowrate was fixed at 0.075 kg/s and annular mass flowrate adjusted from 0.008 kg/s, 0.017kg/s & 0.025 kg/s respectively. In the end, it was concluded that the newly designed integrated system could be employ to obtain both thermal and electric energy.